1. Field of the Invention
The present invention relates generally to a data transfer device, a semiconductor integrated circuit device and a data transfer method, and relates, for instance, to DMA (Direct Memory Access) transfer.
2. Description of the Related Art
In recent years, DMA transfer techniques have widely been used. When DMA transfer is executed, memories, devices, etc. are connected to a DMA controller (hereinafter referred to as DMAC). The DMAC controls data transfer. DMA transfer is disclosed, for instance, in Jpn. Pat. Appln. KOKAI Publication No. H9-223102 and Jpn. Pat. Appln. KOKAI Publication No. 2002-259326. According to the DMA transfer, data transfer can be executed between memories or devices without intervention of a CPU (Central Processing Unit). Thus, the load on the CPU can be reduced, and the system performance can be enhanced.
In the conventional DMA transfer, however, there is such a problem that the efficiency of data transfer would deteriorate in a case where a transfer-source device or a transfer-destination device can execute data read-out or data write only in an in-order scheme.